From 2119f2189df1836d28909fe5a90b3d93638ecf65 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 24 May 2019 11:59:05 -0700 Subject: [PATCH] bpftool: add C output format option to btf dump subcommand Utilize new libbpf's btf_dump API to emit BTF as a C definitions. Acked-by: Jakub Kicinski Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/btf.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 73 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index a22ef65..1b8ec91 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -340,11 +340,49 @@ static int dump_btf_raw(const struct btf *btf, return 0; } +static void __printf(2, 0) btf_dump_printf(void *ctx, + const char *fmt, va_list args) +{ + vfprintf(stdout, fmt, args); +} + +static int dump_btf_c(const struct btf *btf, + __u32 *root_type_ids, int root_type_cnt) +{ + struct btf_dump *d; + int err = 0, i; + + d = btf_dump__new(btf, NULL, NULL, btf_dump_printf); + if (IS_ERR(d)) + return PTR_ERR(d); + + if (root_type_cnt) { + for (i = 0; i < root_type_cnt; i++) { + err = btf_dump__dump_type(d, root_type_ids[i]); + if (err) + goto done; + } + } else { + int cnt = btf__get_nr_types(btf); + + for (i = 1; i <= cnt; i++) { + err = btf_dump__dump_type(d, i); + if (err) + goto done; + } + } + +done: + btf_dump__free(d); + return err; +} + static int do_dump(int argc, char **argv) { struct btf *btf = NULL; __u32 root_type_ids[2]; int root_type_cnt = 0; + bool dump_c = false; __u32 btf_id = -1; const char *src; int fd = -1; @@ -431,6 +469,29 @@ static int do_dump(int argc, char **argv) goto done; } + while (argc) { + if (is_prefix(*argv, "format")) { + NEXT_ARG(); + if (argc < 1) { + p_err("expecting value for 'format' option\n"); + goto done; + } + if (strcmp(*argv, "c") == 0) { + dump_c = true; + } else if (strcmp(*argv, "raw") == 0) { + dump_c = false; + } else { + p_err("unrecognized format specifier: '%s', possible values: raw, c", + *argv); + goto done; + } + NEXT_ARG(); + } else { + p_err("unrecognized option: '%s'", *argv); + goto done; + } + } + if (!btf) { err = btf__get_from_id(btf_id, &btf); if (err) { @@ -444,7 +505,16 @@ static int do_dump(int argc, char **argv) } } - dump_btf_raw(btf, root_type_ids, root_type_cnt); + if (dump_c) { + if (json_output) { + p_err("JSON output for C-syntax dump is not supported"); + err = -ENOTSUP; + goto done; + } + err = dump_btf_c(btf, root_type_ids, root_type_cnt); + } else { + err = dump_btf_raw(btf, root_type_ids, root_type_cnt); + } done: close(fd); @@ -460,10 +530,11 @@ static int do_help(int argc, char **argv) } fprintf(stderr, - "Usage: %s btf dump BTF_SRC\n" + "Usage: %s btf dump BTF_SRC [format FORMAT]\n" " %s btf help\n" "\n" " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n" + " FORMAT := { raw | c }\n" " " HELP_SPEC_MAP "\n" " " HELP_SPEC_PROGRAM "\n" " " HELP_SPEC_OPTIONS "\n" -- 2.7.4